Get CheckboxGridPanel selected rows values, v3.4.0 ?

I'm using Ext.net 1.2 == ExtJs 3.4.0

I wanna add the selected values (Filter with Name, Lname) to an ext's textbox.
I searched , and I could find the below codes, but now I don't know how I can add the the values from var values in JavaScript to an ext's textbox.